Short positron lifetime at vacancies observed in electron-irradiated tungsten: Experiments and first-principles calculations
Short positron lifetime at vacancies observed in electron-irradiated tungsten: Experiments and first-principles calculations
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在电子辐照钨中观察到的空位处的短正电子寿命：实验和第一原理计算
DOI：
10.1016/j.jnucmat.2020.152473
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发表时间：
2020
影响因子：
3.1
通讯作者：
Kinomura A.
中科院分区：
文献类型：
--
作者：
Yabuuchi A.;Tanaka M.;Kinomura A.
一些研究报告称，辐照钨 (W) 的正电子寿命约为 170 ps。该值比孤立单空位计算的值 (~ 200 ps) 要短得多。本研究利用正电子湮灭寿命谱研究了电子辐照钨中正电子寿命~170 ps的缺陷的恢复行为。计算了杂质原子修饰的空位-杂质配合物的结合能和正电子寿命。对于包含用两个氢原子修饰的单空位（V-2H复合物）的缺陷复合物，计算出正电子寿命为169 ps，与实验观察到的171±1 ps的寿命相似。此外，计算出VH和V-2H配合物中氢原子的解离能为1.42 eV，实验观察到正电子寿命约为170 ps的缺陷在623 K下发生迁移。这些与之前报道的热解吸光谱研究的W空位中氘的解离能和解吸温度一致。这些结果表明，在电子辐照的 W 中观察到的空位是氢修饰的 V-nH 配合物。
A positron lifetime component of~ 170 ps has been reported for irradiated tungsten (W) in some studies. This value is considerably shorter than that calculated for isolated monovacancies (~ 200 ps). In this study, positron annihilation lifetime spectroscopy was used to investigate the recovery behavior of the defects with a short positron lifetime of~ 170 ps in electron-irradiated W. The binding energies and positron lifetimes of vacancy-impurity complexes decorated with impurity atoms were calculated. A positron lifetime of 169 ps, which was similar to the experimentally observed lifetime of 171±1 ps, was calculated for defect complexes comprising a monovacancy decorated with two hydrogen atoms (V-2H complexes). In addition, a value of 1.42 eV was calculated for the dissociation energy of a hydrogen atom from the VH and V-2H complexes, and the defects with a positron lifetime of~ 170 ps were experimentally observed to migrate at 623 K. These were consistent with previously reported dissociation energy and desorption temperature of deuterium from vacancies in W studied by thermal desorption spectroscopy. These results suggested that the vacancies observed in the electron-irradiated W were hydrogen-decorated V-nH complexes.
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影响因子：
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作者：
B. Bergersen;M. J. Stott
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影响因子：
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作者：
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DOI：
10.1007/bf01199507
发表时间：
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期刊：
影响因子：
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作者：
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影响因子：
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作者：
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